public void ShowCoursesByMajor()
{
YearTwoCourses = new BindableCollection <CourseModel>(_sqlData.GetAllCourseOptionsByMajor(SelectedMajor.MajorId, 2));
YearThreeCourses = new BindableCollection <CourseModel>(_sqlData.GetAllCourseOptionsByMajor(SelectedMajor.MajorId, 3));
}